Each system that uses SAN fabric switches can use shortwave or longwave optical fiber
connections to connect to application hosts, storage systems, or remote
systems.
The maximum distance between the system and host or the system and the storage system depends on the Fibre
Channel speed and cable type. For all speeds and cable types, the maximum distance is 300 m for
shortwave optical connections and 10 km for longwave optical connections. Longer distances are
supported between systems that use the intersystem Metro Mirror or Global Mirror feature.
When you use longwave optical fiber connections, follow these guidelines:
- For disaster recovery, each system must be regarded as a single entity, which includes the
storage system that provides the
quorum disks for the system. Therefore, the system and quorum disks must be co-located.
-
The maximum distance between nodes within a system is 100 meters. There can be a large
fiber-cable distance between the same nodes in the system. However, the nodes must be
physically co-located for effective service and maintenance.
For example, the nodes can be 300 meters away for 2 Gbs connections. For 4 Gbs connections,
nodes can be 150 meters away from the SAN fabric. In both configurations, the maximum cable
distance between the nodes is 600 meters. However, the nodes must be physically within 100
meters of each other.
- All nodes in a system must be on the same IP subnet so that the nodes can assume the same
system or service IP address.